Two options, if you have a tuner, have the rear O2 sensors shut off, or buy mil eliminators that plug in between the sensor and wire harness to make it falsely read it still has cats
If you don't have a place for the O2's in the new pipe you can always wrap them and Ziptie it out of the way to protect them until you have to use it again
BV heads, P&P lower, comp 218/226 cam, 4.2 bottom end, 3k stall, flow 40's, O/R x-pipe, Pacesetter lt's, SCT xcal2 (93 Ortizperformance tune), Windstar upper, 65mm tb, CAI, 8.8 w/ 3.73's, SFC's, cut springs, KYB shocks/struts, MM LCA's
blower/new cam soon
Dealer for Ortiz Performance, great tunes at a good price!